1. Technical Field
The present invention relates to an endoscope apparatus, a method, and a computer readable medium. The contents of the following Japanese patent application are incorporated herein by reference,                NO. 2010-096279 filed on Apr. 19, 2010.        
2. Related Art
A technique is known for obtaining a fluorescent image via multiple exposure each time respiration or pulse of an organism enters a prescribed state, as shown in Patent Document 1, for example. Another technique is known for capturing an image of a heart only in a diastolic state, based on the waveform of an electrocardiogram, to obtain a detailed still image without blur, as shown in Patent Document 2, for example. Yet another technique is known for capturing a plurality of radiographic images at timings when identical pulse phases are detected from a subject and superimposing these radiographic images on each other, as shown in Patent Document 3, for example.    Patent Document 1: Japanese Patent Application Publication No. 2009-236846    Patent Document 2: Japanese Patent Application Publication No. 2008-93220    Patent Document 3: Japanese Patent Application Publication No. 2008-188165
When capturing an image of a target under observation using weak light with a low intensity, as in fluorescent observation, it is necessary to expose the target to light for a long time due the increased signal-to-noise ratio. If the target moves during the long exposure time, the fluorescent image becomes blurred. Movement of the target is not limited to the pulse-like motion of respiration or a heart beat, and may also include a combination of a variety of movements such as the peristaltic movement of intestines. In this case, image blue occurs when image capturing is performed based on a cardiographic signal or respiration signal. Therefore, there is a problem that weak light images with little blur and high signal-to-noise ratios cannot be obtained.